in src/main/java/org/apache/maven/plugins/jarsigner/JarsignerSignMojo.java [318:323]
private void updateJarSignerRequestWithTsa(JarSignerSignRequest request, TsaServer tsaServer) {
request.setTsaLocation(tsaServer.getTsaUrl());
request.setTsaAlias(tsaServer.getTsaAlias());
request.setTsapolicyid(tsaServer.getTsaPolicyId());
request.setTsadigestalg(tsaServer.getTsaDigestAlg());
}